Reinforcements are used in various industries to provide structural support to or reduce noise and/or vibrations in various products. For example, in the automotive industry, the reinforcement may be used to reinforce beams, pillars, rails, nodes, doors, or roof of the vehicle. The reinforcement may include a carrier disposed in a cavity of the product, and a material layer, such as structural or acoustic foam or an adhesive, is disposed on the carrier. The carrier may be made from plastic or metal bonded with the material layer. Accordingly, the material layer generally has adhesive properties.
In FR 2 749 263 a reinforcement is disclosed, in which a foam in its unfoamed state almost fills the entire space in between the longitudinal ribs and the structure. This is needed as the foam is designed to fill the full chamber. The function of the foam in between the longitudinal ribs is to connect the carrier to the structure to be reinforced.
Sometimes, the carrier includes an array of ribs. The material layer is applied around the carrier in a way that a gap between the carrier and the cavity remains free to electrocoating flow. The size of the gap greatly impacts the effectiveness of the electrocoating process. For example, if the gap is too large and the material layer is relatively thick, the global mechanical performance of the carrier is decreased. For example, the gap may be 6 to 10 mm and partially filled with the unexpanded material layer, which may have lower performance due to a weak bonding between the carrier and the product to be reinforced. If the gap is too small (0 to 4 mm), the electrocoating will not effectively protect against corrosion of the product because there is not enough room for an electrocoating material to flow. Therefore, a reinforcement is needed that allows for effective electrocoating with a smaller or no gaps between the carrier and the product.